diff --git a/modules/input/imquartz.c b/modules/input/imquartz.c
index 67c7d6c..a8ebd02 100644
--- a/modules/input/imquartz.c
+++ b/modules/input/imquartz.c
@@ -132,6 +132,8 @@ output_result (GtkIMContext *context,
   GtkIMContextQuartz *qc = GTK_IM_CONTEXT_QUARTZ (context);
   gboolean retval = FALSE;
   gchar *fixed_str, *marked_str;
+  gboolean needs_commit = FALSE;
+  gboolean needs_preedit_change = FALSE;

   fixed_str = g_object_get_data (G_OBJECT (win), TIC_INSERT_TEXT);
   marked_str = g_object_get_data (G_OBJECT (win), TIC_MARKED_TEXT);
@@ -141,8 +143,8 @@ output_result (GtkIMContext *context,
       g_free (qc->preedit_str);
       qc->preedit_str = NULL;
       g_object_set_data (G_OBJECT (win), TIC_INSERT_TEXT, NULL);
-      g_signal_emit_by_name (context, "commit", fixed_str);
-      g_signal_emit_by_name (context, "preedit_changed");
+      needs_commit = TRUE;
+      needs_preedit_change = TRUE;

       unsigned int filtered =
	   GPOINTER_TO_UINT (g_object_get_data (G_OBJECT (win),
@@ -162,10 +164,11 @@ output_result (GtkIMContext *context,
       qc->selected_len =
	   GPOINTER_TO_UINT (g_object_get_data (G_OBJECT (win),
						TIC_SELECTED_LEN));
-      g_free (qc->preedit_str);
+      if (qc->preedit_str)
+        g_free (qc->preedit_str);
       qc->preedit_str = g_strdup (marked_str);
       g_object_set_data (G_OBJECT (win), TIC_MARKED_TEXT, NULL);
-      g_signal_emit_by_name (context, "preedit_changed");
+      needs_preedit_change = TRUE;
       retval = TRUE;
     }
   if (!fixed_str && !marked_str)
@@ -174,8 +177,15 @@ output_result (GtkIMContext *context,
         retval = TRUE;
     }

-  g_free (fixed_str);
-  g_free (marked_str);
+  if (needs_commit)
+    g_signal_emit_by_name (context, "commit", fixed_str);
+  if (needs_preedit_change)
+    g_signal_emit_by_name (context, "preedit-changed");
+
+  if (fixed_str)
+    g_free (fixed_str);
+  if (marked_str)
+    g_free (marked_str);

   return retval;
 }
@@ -261,8 +271,6 @@ discard_preedit (GtkIMContext *context)

   if (qc->preedit_str && strlen (qc->preedit_str) > 0)
     {
-      g_signal_emit_by_name (context, "commit", qc->preedit_str);
-
       g_free (qc->preedit_str);
       qc->preedit_str = NULL;
       g_signal_emit_by_name (context, "preedit_changed");